Prior studies on preparing melt spun fibers containing poly(phenylene ether) have focused on blends of amorphous poly(phenylene ether) and crystalline resins such as polyamide. Poly(phenylene ether) and polyamide are immiscible. Therefore blends thereof typically form two phases in which the polyamide is the continuous phase and the poly(phenylene ether) is the disperse phase. The properties of the blend are similar to the properties of the crystalline polyamide continuous phase, not the amorphous poly(phenylene ether) phase. Thus, the ease of spinning fibers from poly(phenylene ether)/polyamide blends is determined by the crystalline polyamide. Poly(phenylene ether) and polystyrene, on the other hand, are miscible, forming a single amorphous phase. Therefore the properties of the poly(phenylene ether) affect the ease of spinning fibers from poly(phenylene ether)/polystyrene blends. Previous studies on melt spinning fibers from poly(phenylene ether)/polystyrene blends have given inconsistent results. Some lots of poly(phenylene ether) provide poly(phenylene ether)/polystyrene blends that can easily be drawn down into small denier fibers of less than 10 denier while other lots of poly(phenylene ether) having the identical nominal composition cannot.
It is desirable to be able to manufacture poly(phenylene ether) and poly(phenylene ether)/polystyrene blends that can consistently and reliably be converted into small diameter fibers of less than 10 denier through melt spinning. In order to achieve this end, it is also desirable to find properties of the poly(phenylene ether) that correlate with the ease of spinning fibers from poly(phenylene ether) and poly(phenylene ether)/polystyrene blends.